Oilpan: Fix a raw reference in FramePainter.

Source/core/paint/FramePainter.h

Index: Source/core/paint/FramePainter.h
diff --git a/Source/core/paint/FramePainter.h b/Source/core/paint/FramePainter.h
index 44e1f8135f7c03fe2b1161845a5739780e276708..aaa58b77f0e2a1207cd515b76a062674e69d52d8 100644
--- a/Source/core/paint/FramePainter.h
+++ b/Source/core/paint/FramePainter.h
@@ -6,6 +6,7 @@
 #define FramePainter_h
 
 #include "core/paint/PaintPhase.h"
+#include "platform/heap/Handle.h"
 
 namespace blink {
 
@@ -15,8 +16,10 @@ class IntRect;
 class Scrollbar;
 
 class FramePainter {
+    STACK_ALLOCATED();
+    WTF_MAKE_NONCOPYABLE(FramePainter);
 public:
-    FramePainter(FrameView& frameView) : m_frameView(frameView) { }
+    explicit FramePainter(FrameView& frameView) : m_frameView(&frameView) { }
 
     void paint(GraphicsContext*, const GlobalPaintFlags, const IntRect&);
     void paintScrollbars(GraphicsContext*, const IntRect&);
@@ -26,7 +29,9 @@ public:
 private:
     void paintScrollbar(GraphicsContext*, Scrollbar*, const IntRect&);
 
-    FrameView& m_frameView;
+    FrameView& frameView();
+
+    RawPtrWillBeMember<FrameView> m_frameView;
     static bool s_inPaintContents;
 };